Process of producing coated metal objects.



J. F. MONNOT.

PROCESS OF PRODUCING COATED METAL OBJEGTS.

APPLICATION FILED SEPT. e, 1907. nnnnwnn Jun: 16, 1909. 929,777.

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Patented Aug. 3, 1909.

J. F. MONNOT.

PROCESS OF PRODUCING GOATED METAL OBJECTS.

APPLICATION FILED SEPT. 6, 1907. RENEWED JUNE 16, 1909.

Patented Aug. 3, 1909.

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Inventor:

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' UNITED STATES PATENT OFFICE;

JOHN FERREOL MONNOT, OF NEW YORK, N. Y., ASSIGNOR TO DUPLEX METALSCOMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

PROCESS OF PRODUCING OOATED METAL OBJECTS.

Specification of Letters Patent.

Patented Aug. 3, 1909.

Application filed September e, 1907, Serial No. 991373. Renewed June 1a,1909. been 110.602,!48.

To all whom it may concern:

Be it known that I, JoHN FERREOL MON-a NOT, a citizen of the UnitedStates, and a resident of the city, county, and State of New York, haveinvented certain new and useful Improvements in Processes of ProducingCoated Metal Objects; and I hereby declare the following to be a fulland exact description thereof, such as will enable others skilled in theart to which the invention pertains to make and ractice the same.

My invention re ates to a process of producing ingots and like bodies ofcoated metals, and more particularly to a process of producing cladmetals, by which term is meant bodies comprising a core or base of onemetal (iron or steel for instance), having united thereto, andpreferably inseparably united or welded thereto, a substantial coatingor layer of an unlike metal, (for instance, copper, silver, gold,aluminum, brass, bronze, aluminum bronze, etc.)

In Patents Nose 851,684, 851,993, and 853,716, and in various pendingapplications, I have illustrated and described apparatus and processesfor producing clad metal bodies such as referred to, and comprisimvarious pairs of unlike metals such as referred to inseparably weldedtogether the pairs of metals being in some cases united by anintermediate thin layer of a third metal inseparably welded to both.According to the present process, and'by the apparatus hereinillustrated and described, I produce such coated or clad metal objectsby casting the molten coating metal around or against a metal core orbase in the solid state located in a suitable mold and submerged in aliquid wiping material such as hereinafter referred to, and causing suchmolten metal to displace the wiping material and so to comeinto directwetting contact with the surface of said solid metal object, and tosolidify thereagainst. I thereby. maintain a clean surface of the objectto be coated up to the time of such contact with the molten coatingmetal, and free the coating metal from oc cluded gases and oxidimpurities. avoid progressive contamination of the molten metalso cast,such metal being transferred direct from its melting furnace to the moldwithout intermediate contact with metals which it may dissolve orabsorb. The process particularly lends itself to the I also tionalpurity and freedom from bubbles,

blow-holes, and occluded gases, as a dense, tough and fine-grainedmetal. The base or object to be coated is also, preferably, immersed inthis wiping liquid and is thereby protectedfrom oxidatlon orcontamination said liquid bein displaced from around said base by the moten metal as it rises in the mold, so that intimate contact occursbetween an absolutely clean surface of said base and absolutely cleanmolten coating metal, entirely without intermediate contact of air orother contaminating or chemically active media. V

The core or base to be coated is commonly heated to a high temperaturebefore the molten metal is caused. to contact with its surface; andpreferably this heating is conducted by lacing the said core or base inthe mold in w ich the casting is to be done, said mold containin asufficient guantity of said Wiping material (either soli or molten) tocompletely submerge said base, and then the mo d is laced in a suitableheating furnace (if not a ready in such furnace) and heated Wipingmaterial'may be entirely neutral as regards the metal of the core orbase or oxids and other coatings formed thereon by the action ofcontaminating agents, orit may have more or less cleansing or solventpower. Sodium silicate '(water glass) is one suitable wiping materialwhich may be used. This material, placed" solid in the mold, soon meltsunder the action of the heat of the furnace, but seemsto havecomparatively little solvent power for oxid coatln on iron or steel;such solvent action not bei-n required if the surface of the iron orsteel ase or core be carefully cleaned, as should bethe case, be-

fore said core or base is placed in'the mold. If greater solvent actionas regards oxid or other contaminating coating is desired, borax may beadded in greater or less quantity to the sodium silicate.

The apparatus which I prefer to use in carrying out In process comprisesa furnace having a p urality of heating chambers through which furnacegases circulate successively, said chambers. adapted, to receive themolds in which the casting is to be done. Such molds may be similar, inmaterial and construction, to graphite and other refractory crucibles,and may be rovided with removable sectional liners; t e surfaces ofwhich against which the molten metal solidifies beingeasily ke t trueand smooth and the distance of Whic from the surface of the ature of themolten coating metal.

core or base being easily regulated. The crucibles are commonly. laced,in the first instance, in a preliminary eating chamber of the furnace,wherein the wiping material, it introduced solid into the crucible, iscaused to melt; the cores or bases to be coated being introduced intotheir molds or crucibles while the latter are in this preliminaryheating chamber, and being heated in such chamber to a certain extent.After a time, the molds or crucibles are removed from such preliminaryvheating chamber to an intermediate heating chamber; and after heating insuch chamber fora time said molds or crucibles are removed to afinalheating chamber,

wherein the contents ofsaid molds are raised to the desiredtemperatures. Said molds or crucibles are then returned to' thepreliminary heating chamber, and while there the molten metal is pouredinto them, and is allowed to solidify; the temperature of suchpreliminaryheating chamber being maintained much below thesolidification tern eren the molten metal has solidified, the coatedcores or bases, which may'now be termed clad-metal ingots, are removedfrom their molds and worked in any'suitable manner, either immediatelyor after submission to a soaking heating, with or without intermediatecooling.

By the process above outlined clad-metal ingots may be roduced whereinthe coating is so inseparab y united to the base or core as to beinseparable therefrom by the action of heat or cold or by anything shortof cutting'or grinding it ofl or the action of solvents; it beingimpossible to split the coating off by attempting to cause a cold chiselto follow the line of union, the tool to the contrary tending to divergeinto the one metal or the other and refusmg to follow the line of union.The union roduced appears to be equivalent to a weld etween two bodiesof iron or steel, for example, and I believe it to be a true weld.

In'the accompanying drawings I llustrate tile an of the upper portion ofa mold to which said tile is fitted. Fig. 5 shows a. top.

view, and Fig. 6 a central. vertical section, of a mold fitted forcoatin round cores or bases; a core .or base being slown in lace in themold. Fig. 7 shows a top view, ig. 8 a vertical section, and Fig. 9'another vertical sec tion on a plane at right angles to that of Fig. 8,of a mold fitted for coating rectangular cores or bases; such a core orbase being shown in place in the mold. Referring now to the drawings,and at first more particularly to Figs. 1 and 2, 1 designates arelimlnary heating chamber or pourin g plt 2 an intermediate heatingchamer, and 3 a final heating chamber. Chamber 3 is provided with anopening 4 through which a flame jet mag be projectedfrom a suitableburner, not s own, the flame bein caused to impinge against a suitablepedesta or spreader 5 and then to rise up through the chamber, finallypassingltherefrom through a port 6 and duct 7 into c amber 2, and thencethrough openings 8 in the bottom thereof and a duct 9 into flue 10 atthe bottom of chamber 1 and thence to a suitable ofltake, not shown.Chambers 1 and 2 have pedestals, 11 and 12 respectively, to support theposed of two longitu mal members resting on a slab 13 separating furnacechamber "lfrom flue 10. C amber 1 is jacketed with products ofcombustion, there being on both sides of it spaces 14; connected toofi-take flue 10.

Numerals l5 designate the molds, which usuall are similar in form andmaterial-to crucib es such as are ada ted for withstanding hightemperatures. ithin these crucibles are liners 16 (Figs. 39 inclusive)comprising wedges or liner-sections of refractory material (usuallysubstantially the same material as the crucibles) the outer sides ofwhich correspond substantially in taper to the usual taper of the wallsof the crucibles, and the inner sides of which have such shape as isdesired for the completed ingot, being usually arallel, as ingots withparallel sides are usua l desired.

17, 17 esignate the'cores or bases to be coated, within the crucibles.Preparatory to introducing them into the molds, the cores or bases areusually cleaned thoroughly, as by sand-blasting, pickling, etc. so as toreand when introduced are centered accurately with respect to thesurfaces of the crucible-liner; which is usually done by introducing asuitable number of spacingieces into the mold before the core is introneed, then introducing the core, and then removing the s acing pieces;said spacing ieces bein of a t ickness correspondlng to t e intendedistance between the sides of the core and the sides of thecrucible-liner. To hold the core stationary and truly central at thetop,it is usually provided with a spacing piece 18 of refractory material,held in place by the ring-bolt 19 by which the core is handled. Beforethe cores are introduced into the molds, the latter contain a suitableamount of -molten wiping material, such as above referred to; and as thecore is introduced into its mold this wilping material rises around itand complete y covers it, so protecting it against oxidation or attackby furnace-gases. a

The GIUGIblG with a core therein remains in chamber 1 until its contentshave been heated therein sufficiently and until there is a vacancy inone of the chambers 2, and is then lifted out of chamberl and-dc ositedin chamber 2. After being heate sufliciently therein, and when there isa vacancy in one of the chambers 3 the crucible-is lifted out of chamber2 and deposited iii-chamber 3. When the contentsofthe crucible have beensufficiently heatedvinchamber 3 (which is told by a peculiar surfaceappearance which the workman soon learns to recognize), the cruciblewith its contents is removed from chamber 3 and restored to chamber 1,and the molten coating metal, previously melted in another furnacenot'shown, but which may be of ordinary construction, is pouredin'to'the crucible or mold, displacing the wiping material from contactwith the core andso coming into complete wetting contact with a cleansurface of saidcore. To facilitate the flow of the molten coating metalinto the mold without erosionof the soft highly heated topof the coreand ringbolt 19, and totake care of the displaced wiping=material, Icommonly'fit to-the mpld,

just before the;pouring,-a pouring tile 20 of suitable refractorymaterial, said pouringtilehaving a central partition-21 adapted-to restupon thespa'cing piece 18 (said partition 21 havinga cavity 22 toreceive the said ring-bolt 19) and having passages 23 and 24, of which23 is'intended toreceive the stream of molten-metal and direct it overthe ed eof spacing piece 18 to the annular space etween the core and-thesides ofthe mold,-and '24 is intended to receive-the displaced moltenwiping material. Passa e 24 is preferably large enough to contain t eentire mass of displaced wiping material, without overflow; but to takecare of overflow, if it occurs, a lip 25 is provided which willdischarge any overflow beyond :the'edge of the mold. The mold havingbeen poured in the manner stated, the molten metal is allowed tosolidify, after which the pouring-tile (the wiping material in which hasalso solidified) is removed, the completed ingot removed from the mold,the liner coming out with it, and then the sections of "said liner areremoved from the ingot and after theyhave cooled sufiiciently aredressed tosize and resurfaced if necessary, and are then placed back inthe same or another similar. mold, which may then be placed-in thefurnace chamber 1, with a suitable quantity of wiping material therein,and the operation repleated. The wiping material'which solidies in thepouring tile may be removed therefrom, broken up, and used over again anumber of times.

It is desirable that certain metals, copper for example, shall be cooledas soon as possible after casting; and it is also necessary in certaincases to guard against more rapid cooling at the ends than near thecenter of the ingot, which may cause the cast metal to be drawn outsomewhat at the center,: roducing an ingot of irregular size, whic isdifficult to roll properly. To cause rapid coolingI direct a stream ofcold airagainst the sides and bottom of the crucible as soon as thelatter has been withdrawn from furnace chamber 1, regulating theapplication of this blast of air so as to cause substantially uniformcooling throughout the length of the ingot; and as soon as the castmetal has set and the in ot has been removed from the mold and t e linersections strip ed there from the ingot may be cooled. T eingot is then,at any suitable time, reheated, and worked under the hammer, betweenrolls, or-in a ress, vto compact the metaland to reduce t e ingot todesired forms. In general, the coatings formed as above described arevery dense, uniform, and free from pits, blow-holes, blebs, porosity,etc. land the metal is very soft, tough and ductile.

In for-min weld-unions between the core or article to e coated, and thecast-on coating, as is usually desired, I commonly heat the said core,immersed as described-in the molten wiping material, to-or nearly -to-anorange heat; 1f the core be of iron-or steel, a low welding heat such asis well known to blacksmiths bein suitable, and it being I easy to tell,by t e surface appearance of the 'molten wiping material in the -mold,when-this heat is'reached. Likewise, when such weld-unoins are desired,the -.molten coatingmetal is commonly heated to atemperature much abovethe melting point and ordinary casting tem erature and approaching orequaling the "su ermolten temperature (2400 to 2800 F. m the case ofcopper and silver and somewhat lower in the case of aluminum) referredto. in my Patent No. 853,716 above mentioned. It is robable that for theformation of such a we d-union between unlike metals absolute wetting ofthe solid metal bythe molten metal is required, and that such wettingdoes not take place, uniformly or sufiiciently, unless the molten metalcontacting with the surface of the solid metal be at a temperatureconsiderably above the ordinary casting temperature likewise it ispossible that at such high or supermolten temperature the molten metalacquires the power of uniting with the solid meta1 by an actionanalogous to,

or which actually is, a chemical action.

The rocess and apparatus above described l end themselves well to theproduction of ingots of various cross-sections and tothe production ofingots coated on certain sides only, and'have theimportant advantagethat molds or crucibles need be only a little larger than the ingots tobe produced; which at once permits the coating of larger cores and theuse of smaller and less expensive crucibles, as compared with the.

rocess and apparatus of my said Patent 0. 853,716. In Figs. 5, 6 and 7,I have shown a mold adapted for forming rectangular ingots coated ontheir broader sidesonly; the narrow sides, or edges, of the core fittingclosely against the mold-liner, so that such sides are not coated. Whilethe ingot to be roduce'd is rectangular, the crucible itsef ispreferably oval, to' avoid the well-known weakness at the corners towhich rectangular crucibles are liable.

In Figs. Sand 91 have shown a mold adapted for forming cylindricalingots.

It will be obvious that by the use of suitably-formed molds,liner-sections, and cores, ingots of various other forms may beproduced. V

The conduction of the heating gases from chamber 3 to chamber 2 andthence beneath and around chamber 1 greatly economizes the consumptiomoffuel, chambers l and 2 being in'efi'ect heated by waste gases; and thegradual heating to which the crucibles are subjected greatly increasestheir life. The conduit 7, conveying the heating gases from chamber 3 tochamber 2, comprises a metal shell lined with refractory material, a

26; and said conduit is removable, as shown,

togetherwith orjse aratelyfromthe covers a 27 and 28 of charm ers Z-and3 ,to. permit u insertion .and withdrawal of the crucibles. To permitthe introduction of the prongs of crucible-tongs beneath the crucibles,

pedestals 5 and 12 are provided with refurnace gases, air etc., as wellas by 1 tallic inorganic material. In

cesses' 29; and the space between the longitudinal supports 11 ofchamber'l serves the same purpose.

In many cases it is desired that the coating formed as above describedshall be exceptionally pure; In the production'of ingots for copper-cladsteel electric conductors, for example, it is desirable that the coppershall not be contaminated with iron or other impurities during theprocess. I have found that highly heated copper is exceedingly subjectto contaminatlon by rolonged contact, or successive contacts, w ile inthis highly heated condition, to iron or steel. By the method abovedescribed, the copper is preserved from contamination, being oureddirectly from the melting furnace t rough the wiping'materia-l mentionedinto the mold and-there solidifying against the object to be coated,

In another application for Letters Patent, i

executed concurrently with this, (Ser. No. 391 ,674, filed Sept. 6,1907) I have set forth at length the advantages of casting through alayer of wiping material, when forming metal ingots; one advantage beingthat the stream of molten metal, in passing through the wipin material,is freed of entrained .gases, oxi and other impurities, so that themolten metal appears at the base of the body of wiping material in achemically clean form, so far as the presence of air or moisture isconcerned, and the several particles or drops have a clean metallicsurface, enabling them to unite with each other to form a homogeneousflawless body of metal, and enabhng them to unite with the clean surfaceof the core to form a permanent union therewith. And since there isnofilm of absorbed air or moisture on the surface of the mold, and sinceair and gases are not entrained by the molten metal or occluded therein,the surface of the in ot cast as above described is practicallyfree remblow-holes, blebs and otherflaws. Since in my said companionapplicationI claim broadly the casting of molten metal through a layerof molten wiping material, Ido not claim the same herein.

Instead of employing sodium silicate as c the wiping material, I mayemploy other alkalinesilicatea. 'or fusible material containingalkaline' silicate, glass for example, or I may employ borax or otherfusible non-meener'al I prefer that the material used sha havenoparticular solvent or chemical effect on the article to be coated, andhence do not ordinarily employ borax unless neutralized partly or whollyby soda; though sometimes borax is added to the wi in material todissolve ofi' traces of super cia oxid which the article to be coatedmay have; i

In some cases, when coating a metalof eaa'rrm point, steel for eiramplewith a metal'foflbw melting or volatilizing point, or withanalloy-containing'an ingredient, oi-low stated, and which unitesreadily and inseparably with the metal for the main coating at a lowertemperature; or,I ma form on the object to be coated a thin coating ofsuch intermediate metal by the castlng rocess above described, and thenform an ad itional coating of the main coating m'etal by the castingprocess above described.

The core or base need not be iron or steel, but for most purposes aniron or steel base will be referred. In this specification and in theollowing claims I employ the term iron to designate all forms of ironand steel, including the various compound-steels, such a tungsten steel,titanium v steel, vanadium steel, chrome steel,nickel steel, cobaltsteel, manganese steel, etc.

While I particularly contemplate employing my process in the productionof compound metal ingots, comprising two or more unlike metalsinseparably united or welded, the process and the apparatus abovedescribed are applicable to the production of in ots comprislng layersof the same metal or di erent rades of the same metal, or of a metal andan alloy thereof.

What I claim is:

1. The process of producing coated metal objects, which consists insubmerging a metal article to be coated in a bodyoi molten inorganic wiing material contained within a suitable mo d, and pouring moltencoating metal into said mold and causing such molten metal to displacesaid molten wiping material and to contact with the object to be coated,and then permitting such molten cast metal to solidify.

2. The process of roducing coated metal objects, which cons sts inheating a metal article to be coated in a suitable mold while submergedin a body of molten inorganic wiping material, and ouring molten coatingmetal into said mo (1 and causing such molten metal to displace saidmolten wiping material and to contact with the object to be coated, andthen permitting such molten cast metal to solidify.

3. The process of producing coated metal objects comprising unlikemetals united toether, which consists inpouring afmolten ody of one suchmetal into a suitable mold zoontatining a solid body of the'other metal."submerged 1n molten inoranic wiping ma- 'terlal and causin such In tencast metal to "then solid displace said mo ten wiping material and 'tocontact with, the object to be coated, and

fpermitting such molten cast metal to 4. he processof producingcoatedmetal objects com rising pnlike metals united to gether, whicconsists in pouring a molten odyof one such metal into a suitable moldcontaining a hi hly heated solid body of the other metalsuhme rged ininorganic wipin material and causin such molten cast metail to displacesuch mohen wipin material and to contact with the object to e coated,and

then ermitting such molten cast metal to solidi. A

5. he process of rod'ucing ob'ects-comprising unlike metals inseparab yunited, which-consists in curing a molten body of one such metal, heatedto a temperature much above its meltin oint, into a suitable moldcontaining a bi y heated solid body of the other metalsu merged inmolten ins organic wiping; material and causing such molten cast metalto displace such molten wiping. material and to contactwith the saidbody of the other metal and to solidify therea ainst.-

6. T e process of roducing objects comprising unlike meta s inseparab yunited, which consists in pouring a molten body of one such metal into asuitable mold containing ,a solid .body of the other metal submerged inmolten inorganic wiping'mat'erial and heated to a welding heat, andcausin such molten cast metal to displace suc molten Wi ing material andto contact with the said ody of the other metal and to solidi? thereon.

7. he process of roducing objects comprising unlike metas inseparab yunited, which consists in pouring a supermolten body of one such metalinto a suitable mold containing a solid body of the other metal Isubmerged in molten inorganic wiping material and heated to a weldingheat, and causing such molten cast metal to displace such molten wipingmaterial and to contact with the-said body of the-other metal and tomold containing a solid body of ferrous metal submerged in molteninorganic wiping material, and causing such molten cast metal todisplace such molten wiping material and to contact with the said bodyof ferrous metal and to solidif thereon;

9. The process 0; producing objects'com- 10 a prising iron andconpermseparabl united,

1 l i terial, andcausing such molten cast meta-1 to separably united,which consists in pourin molten eupriferous metal into asuitable 11101 Mcontaining a solid body oflerrous metal sub? H181 ed in a moltenInorganic wiping materiz and causing such molten cast metal todisplacesuch moltenwiping material and to contact with. said body of fei'i'ous Inet al cover said metal body, heating the mold and 3 its contents andthereby raismg said metal and to soliclify thereon. v i k t 10. Theprocess of producing objectscom which consists in pouring supernio ten0055- pcrin'to a suitable mold containing a be y of solid iron heated towelding heat, and suh merged in a molten inorganic wiping madisplacesuchmolten Wiping material and to contact with the iron and solidifythereon.

11. The rocess of Froducing objects com? prising un ike meta s insearably united which consists in placing a 0 can body of one, metal, in asolid state, into ing suificient inorganic wiping material to body to awelding heat, and pouring highly heated unlike metaldnto: said mold andcausingsuch molten cast metal to displace such moltenwiping material andto contact v with the solid metal and solidify there:

against.

prising ferrous and cuprife'lous metals int objects which eonsistsiinsubmergmg a metal object to be coated inraihody silicatein amold,pouring A metal through such bod into Hcontact wit Q a saidobject andthereby isplacin ermitting iv the? Incl metal to so idify in lcontactwith 13.The process of producing c objects which con'sistsin subme Ionsmetal object in a body of silicate in a mold, pourin Incl ro s coatingmetal throng sue contact. with said objec' placing; said: body; and t ta mold contain- 12". Theprdcesof'producingcoatedmetal: 1

and then molten 10min g the body; ten; coating saidohject,

oeted metal nse e alkaline en nonfer-j hbodyint'oi and therebydisnenpermittin the a a k l n n molten non-ferrous coating metal to so idifin contact with said ferrous 14. The process of produci'ng coated metalobjects. which consists in en 50 i 'rous metal object in a body of ansilicate in a mold,

metalobject,

bmerglng a fer alkaline I pouring molten copper.

through "such body into contact with said object and thereby displacingsuch body; and then permitting the copper to solidify in contact withsaid ferrous metal object.

In testimony whereof I afiiX m in the pfesence of two witnesses. j

JOHN FERREOL MON Witnesses: a v

H. M. MARBLE,

K. P, MGELROY;

NOT.

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